Let V = <1, 3, 3>. Find a unit vector for this.

Question

I have 1/sqrt(10), 3/(sqrt(10)), 3/sqrt(10). I cannot understand why this is not the answer. It is pointing in the same direction.

Answer 1

Divide the vector by its magnitude.  That gives its unit vector.  In addition to pointing in the same direction, its magnitude must be 1.

 

u = unit vector

 

u = v / |v| 

 

|v| = √(1² + 3³ + 3²) = √19

 

u = <1/√19, 3/√19, 3/√19>